IT might seem an unusual ingredient for plant fertilizer, but metal dust from spent household batteries are being tested as potential crop nutrient supplements by an Australian recycler and supplier of battery materials.

After collecting recycled everyday alkaline batteries from local pick-up points around the country and then shredding them, Lithium Australia NL conducted short-term trials by testing the dust — containing valuable trace element nutrients such as zinc and manganese — on pots of wheat in glasshouses.

The tests, which were carried out at the company’s Envirostream Australia Pty recycling facility in Victoria, showed a “significant uptake” of the metals in wheat on local low-quality soil, according to managing director Adrian Griffin, though it was a slower process in comparison to fertilizer-grade sulphate products.

“We would anticipate that the results would be significantly better than that on more normal soils that we see in the wheat belts in Western Australia,” he said.

With annual sales totaling around 6,000 tons nationally, alkaline batteries — used in typical household items — are notoriously under-recycled, according to Lithium Australia, citing research showing that 97 percent of batteries end up in landfill.

The results have led Lithium Australia to commit to further larger-scale testing, aimed at evaluating the performance of the extracted metals against commercial fertilizer products. Those would likely kick off in the current growing season after the end of the financial year, said Griffin.

“We want to accelerate the trials as rapidly as we can,” he said. Along with domestic projects, the company was also considering rolling them out off-shore, he said. The trial mixtures would remain broad at this stage, rather than tailoring them for particular agricultural products and regions.

Secondary industries like scrap metal producers that can re-use batteries don’t have “much of an interest” in the spent alkaline versions — the largest proportion of the facility’s collected batteries recycled at Envirostream, Griffin said. That’s because they had a lower value when compared with their longer-lasting lithium relatives, which are an essential component in electric vehicles, he said. (SD-Agencies)